Ear glowing translucency?

Darth_Biomech

I want to make an animation on the Unreal engine. One of the characters have large ears, so I wondered if it is possible to achieve a shine-through effect like in this photo:

I tried checking SSS shader, but it seems it's purpose is more to "wrap" the lighting around the corners or the geometry to achieve soft underglow effect on the surface in areas around shadow edges rather than simulating true translucency, not sure it is applicable of simulating light coming through thin things.

I understand that I'll need to bake a "thickness" map for my character, but other than that I have little clue as to how to proceed.

Obscura

you dont actually need a thickness map, though it can be used to give more control. Use SSS profile instead of the simple sss shading model, and enable "transmission" on the light source. Also tweak the sss profile parameters to get the desired result.

Darth_Biomech

Thanks! I understand it that in this case thickness map will act like a mask for the strength of the effect, right? Or will it just mask its visibility?

Obscura

Yes. But the actual thickness seems to be approximated mostly correctly even without a thickness map.

Darth_Biomech

Obscura said:

Yes. But the actual thickness seems to be approximated mostly correctly even without a thickness map.

Oh, maybe, but then it is useful in case of objects that aren't just made out of uniform substance. In a living organism some parts will be more translucent while others will have stuff blocking the path, like bones, or made out of different tissues, I'd presume.

MostHostLA

Unfortunately, at least as of .25.2 the thickness map is either bugged out or working with a very special feature.
The effect comes on/off as you reach a value of .11 gray, so in a gradient black to white you get a hard line across the thickness texture instead of a gradient fade.

Still waiting on an official response for the bug report. Meanwhile using the bugged out map provides a more reliable result then no map at all for humans. Mostly because without it you get light artifacts on thick parts of the body, like thighs, during movement.

Obviously this is coupled and exacerbated by my personal light settings. If you aren't working with dynamic lighting you may have an easier time balancing things... 

Darth_Biomech

Dang, this is crap news then. =\ Hope it get fixed soon.